If you want an inexpensive frame, Craigslist can be a great source. As for mattresses, it really is good to test out some in person, unless it's for a spare room, which I know it isn't. IKEA has reasonably priced ones. Or look for some major mattress warehouse type place. You know, some place called like "Mattress City" or similar. They may have a New Years sale going on. It's possible that a place like Sears (if there is one near you) may have some.